Apparatus for developing sensitized layers



2,240,409 APPARATUS FOR DEVELOPING SENSITIZED LAYERS S. H. MORSE April 29, 1941.

Filed A rilzo, 1.93s

2 Sheets-Sheet l April 29, 1941. s H MORSE 2,240,409

APPARATUS FOR DEVELOPING SENSITIZED LAYERS Filed April 20, 1938 2 SheetsSheet 2 Patented Apr. 29, 1941 2,240,409 APPARATUS FOR DEVELOPING SENSITIZED LAYERS Sydney Harold Morse, London Wall, London, England, assignor to Wood, Mallabar and Company Limited, London, England, a corporation of Great Britain Application April 20, 1938, Serial No. 203,206 In Great Britain April 26, 1937 6 Claims. The invention relates to apparatus for developing sensitized layers, in which the said layers are subjected to the action of ammonia or other developing gas.

In apparatus of this kind it is essential that Whilst the developing medium must be maintained at the right degree of humidity in order to obtain perfect development, at the same time moisture must not be allowed to condense upon the surface of the sensitized layer as this results in imperfect development.

The object of the invention is to provide a simple and compact apparatus for developing sensitized layers by the action of ammonia or other as which is in a continuous humid state in which the moisture content of the developing gas is prevented from condensing upon or in the immediate vicinity of the layers whilst they are passing through the developing tank.

The invention consists in apparatus for developing sensitized layers by ammonia. gas or other vapour produced by evaporating a liquid, in which a flow of cold air is caused to pass over at least one of the longitudinal walls of the developing tank thereby to reduce the temperature of said well relatively to that of the remainder of the tank and cause any condensation which may take place inside thetank to be concentrated on said wall away from the said layers.

The invention also consists in the further features hereinafter described and claimed.

The invention will now be described with reference to the accompanying drawings, in which:

Fig. 1 is a cross section through the apparatus.

Fig, 2 is a fragmentary front elevation.

Fig 3 is a fragmentary elevation partly in section on the line A.A of Fig. 1.

Fig. 4 is a fragmentary elevation partly in sec tier. on the line 13-23 of Fig. 1.

Incmylng the invention into efiect, there is provided a rectangular or box-shaped housing of sheet metal comprising a back cover plate a and top cover plate I) extending between a pair of end plates secured to a base (I and held together by any convenient means such as stretcher bars e. The said housing is provided with a front cover plate I which also constitutes the front wall of a developing tank g of oblong form extending from end to end of the apparatus and closed at its ends and on top, by the end plates c and top cover plate 12 respectively of the housing proper. At its lower end said tank is closed by a bottom plate )1. arranged some distance above the main base plate d so as to leave a horizontal space 1 extending the whole width of the housing and from end to end thereof. The tank a is completed by the rear plate 1 which extends from one end plate 0 to the other parallel to the outer rear cover plate a on the inside thereof and at a distance therefrom so as to leave a vertical space It extending from top to bottom of the housing and also from end to end thereof, the vertical space It at its lower end communicating along the whole of its length with the longitudinal space i.

Mounted within the tank 1 and extending substantially the whole length thereof, is a revolving cylinder 1 preferably or porous material such as fibrous cement and onto which the sensitized layers are adapted to be fed, the said layers being retained upon said cylinder by means of an endless open mesh wire belt m supported upon rollers n rotatably mounted at their ends in the end plates 0. 1

A longitudinal gap 0 isprovided in the front plate I opposite the cylinder 1, for the purpose of permitting the sensitized layers to enter and leave the tank. Connected at its inner end to the upper edge of the gap 0 is a plate 12, which after sloping slightly downwards away from the front plate I for some distance is then bent vertically downwards to join the base plated. The plate 31, which at its inner end penetrates within the tank a as far as the surface of the cylinder 1, serves as a table for feeding the layers into the tank and onto the cylinder, and at the same time prevents the escape'of the developing gas from the upper part of the tank.

An additional guide member or may be provided immediately above the feed tablep where it enters the tank, which guide member also extends within the tank as far as the cylinder and ensures the layers being guided between the cylinder and the wire mesh belt.

A sec'ond plate r is connected at its inner end to the lower edge of the longitudinal gap 0, which plate also slopes away from the front plate I but only for a relatively short distance, after which it is bent vertically downwards parallel to the outer plate 11, the two plates 9 and r constituting between them a delivery chute s which is open at its lower end and through which the layers are discharged after passing through the tank. In order to guide thedeveloped layers into the delivery chute s, a roller t, preferably of resilient material such as rubber, is rotatably mounted inside the tank adjacent the lower edge of the gap 0 which roller also serves as a seal to prevent the escape of gas from the lower part of the tank g. To assist further, the removal of the develpart of the tank and not on the sensitized layers. vapor therein, mea

6. An apparatus for developing sensitized laywithin said tank a ers by means of ammonia or other vapor, comparallel to the re prising an external housing having a rear wall, ing said opening a substantially gas-tight developing tank hav- 5 layers through th ing a rear wall spaced from the rear wall of said the passage throu housing to form a space extending from top to walls of a flow of bottom of and along the whole length of said condensation oi v tank, an opening in the front wall 01' said houswall of said tank ,ing, means for heating said tank to generate 10 us including a roller disposed nd having its longitudinal axisar wall of said tank for sealand for feeding the sensitized e tank, and means for causing gh the space between said rear cold air sufilcient to cause any apor to take place on the rear and not on the sen sitized layers. SYDNEY HARO LD MORSE. 

